The present invention relates to an electronic instrument.
In recent years, a portable music player with a built-in hard disk has become popular. In the portable music player, music data compressed according to MP3, ATRAC, or the like is downloaded from a personal computer (PC) and stored in the hard disk of the portable music player. The user enjoys music by reproducing the stored music data.
However, the hard disk (storage) in which the music data is stored cannot be easily removed from the portable music player. Therefore, it is difficult to exchange the music data between friends, whereby convenience to the user is reduced.
In recent years, a high-speed serial interface such as USB 2.0 has attracted attention. As the technology of realizing such a high-speed serial interface, various related-art technologies have been proposed (e.g. Japanese Patent Application Laid-Open No. 2002-343864).
In the USB standard, a downstream port of a host, such as a PC, is connected with an upstream port of a device (peripheral), such as a portable electronic instrument, through a USB cable, so that data is transferred between the host and the device. Therefore, a device-side electronic instrument is generally provided with only the upstream port. If the electronic instrument is provided with only the upstream port, data cannot be transferred by causing the electronic instrument as the device to operate as the host.